Rotary sectional bit



Feb. 18, 1930. A w, v SEH-'ERT f l l,747,909

ROTARY sEcTIoNAL BIT Filed May 29. 1922 'Patented Feb. 18, 1930 UNITED STATE-s PATENT OFFICE WILLIAM' V. SEIFERT, OF DENVER, COLORADO, ASSIGNOR TO THE UNXV'ERSAL ROTARY BIT COMPANY, A'COBPORATION OF COLORADO ROTARY sEc'rIoNAL Brr Application led May 29, 1922. Serial No. 564,520.

The object of this invention is to provide a-highly efficient rotary bit for earth boring and the like, and more particularly for oil well drilling. i

The invention comprises aplurality of bit sections: adapted to be removed from one anotherand to`be attached to one another to build up a bit of such length and diameter as desired. The .sections are' preferably shoulderedv and carry cutting discs on'their sidesv set at such angles to the radii of the sections as to cause the trailing edges of the discs to clear the walls of the holes being formed. The point of the bit carries at its l5 extremity a plurality of cutting discs set at various langles and in various positions, these discs being of different sizes and arranged `to start the hole and cutthe bottom ofthe same with maximum efficiency. A valve controlled water passage leads through the entire bit for washing the cut rock and earth from the point vof the bit and upward along the sides thereof. Means areemployed at' the upper end of the bit for protecting the discs and properly guiding the bit when being lowered through the well casing or being withdrawn from the hole and upward through the casing.

In the accompanying drawings, wherein certain embodiments of the invention are disclosed by way of example,

. Fi 1 is a side elevation of the bit as indicate by lines 1-1 of Figs.`2 and 3;

' Fig. 2 is a view taken on the line 24-2 of Fig. 1,; e v

Fig. 3' isa fragmentary vertical sectiontaken on line 3-3 of Fig. 1;

Fig. 4 is a sectional., detail taken on line 4-4 of Fig. 3;

Fig. 5 is an end elevation of the point of Vthe bit as indicated by the line 5-5 of Fig. 1; Y

Fig. 6 is a detail showing the guiding means which protects the discs when the bit is moved through theV casing. l

The bit'comprises a plurality of sections 10..of graduated sizes, each of which has at oneend a threaded socket 12 and at the other end a threaded stem 14 whereby the sections maybe connected-together to build up a bitA for drilling a hole -of such diameter as may be desired. The sections 10 are shbuldered annularly as indicated at 15, as many shoulders being provided as desired, and shown on .the drawings as having one, two'and three shoulders variously. Upon each annular portion thus formed a pair of oppositely disposed cutting discs 16 are provided, the pairs of discs on adjacent sections being odset laterally about 90, whereby four rows of discs are provided at the sides of the assembled bit. Each disc 16 bears on a boss 17 and is mounted thereon by means of a screw 18 and an anti-friction bearing or washer 19. The axis or center line Lv of each screw 18 (Fig. 4) is out of line with the radius R of the section 10 about 'as indicated so that the forward and lower cutting portions a of the f discs are set farther outward` from the axis of rotation of the bit than are the trailing edges orportions positively clear the wall just formed.

In order that the bit may be guided into and through the well casing (not shown) and the stem 14 of the section `10 and has an extending threaded portion 25 adapted to re-y ceive the lower end of the drill stem for driving the bit.

A water assageleads through all the sections as in 'cated at 26, and one section has a cavity 28 beyond its socket 12 which receives a ball or other check 30 pressed by spring A32 to prevent return of water and grit, mud or the like.v

The point of the bit is in the form of an end section 40 which may carry'on its`side a disc 16 or a slightly differently positioned .lise 116, Fig. 5. The tip 42.11as a plurality 'of fiat lside, faces 44 at different distances from the axis of the bit, and against these faces. several discs 45, 46, .48 and 50 are carried upon screws 118 none of which are radially disposed. These discs are of different sizes and have different arrangements and positions with respect to said axis, so that the cutting edges thereof are disposed at different angles to the axis and are at different distances therefrom. Thus the disc 48' is large and has its larger face disposed ,o against the respective face 44 while its cutting edge is directed inward toward the axis of the bit. This brings the cutting edge of disc 48 lowermost and close to said axis so that it cuts at the extreme bottomof the hole. The disc 46 is smaller and has its large face also inwardly disposed, but its cutting edge is directed outward and is farther from said axis and is higher in the hole, thus cutting the hole larger. Disc 50 is also small and has its larger facel inclined outward from the axis and outwardly disposed with its cuttin edge still farther from said axis and hlgher than that of disc 48, so that it cuts the hole still larger. Disc 45 is on a horizontal axis with its larger face outward and its cutting edge lying somewhat beyond the side of the section 40, thus cutting at a point more remote yet from the axis. It will be apparent that the disks arranged on the tip 42 as shown and hereinabove described collectively provide a cutting element which operates in auger fashion to bore` a hole of gradually increasing diameter, in advance of the cutters on the body section of the bit, which by engagement with the wall of the opening at progressively increasing distances from the axis of rotation, gradually increase the excavation to the desired diameter. The water passage leads through section 40 and is provided with branches for discharging water directly upon some of the discs at least.

Inasmuch as the clearance around the sides of the bit is equal only to the distance between the walls of the Sections and the cutting edges of the discs, the water being 3. A drill bit comprising a rotary body, a boring elementat the lower end thereof, including a plurality of cutting disks mounted exteriorly thereof with their perpheries exposed and rotatable about individual axes, the disks being arranged relatively to each other and to the axis of the body to collectively bore a hole in auger fashion, andcutting members onthe body above said element, adapted to engage the wall of the bore.

4. A drill bit comprising a'body rotatable Aabout a vertical axis, and a plurality of exteriorly located disks rotatably mounted substantially at the bottom thereof in ixed relation to each other, the axes of rotation of said disks being inclined with reference to a horizontal plane, said disks being arran ed to vwork at different elevations and at di erent distances from the center.

5. A bit for deep Well drilling through earth and rock comprising in combination a bit body rotatable about alvertical axis, a plurality of exteriorly located rotatable cutters mounted on the bit body at different distances from the axis of the bit and at different elevations and in fixed relation to each other, said cutters being of circular frusto-conical shapel with their cutting edges formed b the conjunction of the conical surface wit the larger circular end of the cutter and being mounted with the smaller end adjacent the body of the bit, the respective cutter pumped through the passages 26 willlcause rapid passage of -Water and loose earth or rock upward past the sides of the bit and to the top thereof, thus keeping the j hole clear. I

I'claim: 1. A rotary drill bit having cutting discs secured tothe sides thereof, and inclined guards removably mounted on the top thereof and overhanging the discs to guide the bit during movement and protect thediscs. 2. A rotary drill bit having a tip provided with a plurality offaces, and a plurality of cutting discs mounted upon said faces at different distances from the axis of the bit, one of lsaid discs extending .longitudinally from the tip farther than the others and having the cutting portion of its. edge lying 65 closer to the axis of the bit than the others. 

